The vehicle heaters used in large motor vehicles, e.g., buses or trucks, to heat, for example, a respective interior space or to preheat a drive assembly also have, in general, large dimensions to provide a sufficiently high heat output. This means, especially in case of the use of fuel-operated vehicle heaters, that, for example, a combustion chamber has such large dimensions that the mixture of fuel and combustion to be burned therein will have sufficient space for this combustion. The fuel delivery device used to feed the fuel and the combustion air delivery device used to feed the combustion air also must have correspondingly large dimensions. A vehicle heater dimensioned for providing a comparatively high maximum heat output may have the shortcoming that the possibility of accurately controlling or regulating the heat output is limited in the range of very low necessary heat outputs because of the comparatively small quantity of fuel to be burned in this case and that there is a risk that the combustion may be compromised, for example, there is a risk of flame blow-off. Such large-sized vehicle heaters are also oversized for smaller vehicles, which may lead to the need to provide a comparatively large number of models of vehicle heaters having different dimensions for vehicles of different sizes.